The proposed studies are designed to assess the ability of burned animals to process T-cell dependent and T-cell independent immunogens, and to compare the resulting antibody responses with those observed in normal animals. Particular attention will be given to the comparative role and function of T and B lymphocytes, and to the possible effects of thermal injury upon humoral responses. The test system to be used will be based upon determination of humoral responses of normal and burned mice to sRBC, sRBC-TNP, and Ficoll-DNP. Such in vivo studies will provide data on the kinetics of antibody formation in burned animals, and will be the basis for a search for the mechanisms responsible for the apparent inhibition of T-cell helper function that has been documented in the course of severe thermal injury. The influence of serum and lymph samples obtained at various intervals after thermal injury . The influence of serum and lymph samples obtained at various intervals after thermal injury upon primary and secondary in vitro responses to the above listed antigens will be tested, utilizing the methods of Dutton and his associates. The eventual aim is to isolate and characterize biologically active materials that may be released into the host's circulation as a consequence of thermal injury.